On the tensile and compressive behavior of a sandwich panel made of flax fiber and agglomerated cork

Author(s):  
Prabhakaran Sivalingam ◽  
Krishnaraj Vijayan ◽  
Senthilkumar Mouleeswaran ◽  
Vishwapriya Vellingiri ◽  
Suresh Mayilswamy

Sandwich panels are used in buildings because of their light weight, thermal insulation, sound absorption, and better mechanical properties. Material scientists have been trying their best to replace synthetic materials as these are non-biodegradable. Stringent environmental policies, need for eco-friendly products, and problems in end-of-life disposal have made natural materials in sandwich panels the need of the hour. This research work attempts to replace the synthetic sandwich panels with natural sandwich panels without sacrificing the performance. The natural sandwich panels used in this work had agglomerated cork as the core and flax fiber as skin reinforcement. A vacuum-bagging technique was used to manufacture these panels with three core densities and three skin reinforcements. The performance of these panels was confirmed by conducting flatwise tensile, flatwise compressive, and edgewise compressive tests as per the American Society for Testing and Materials standards and the results are discussed in this article. The specific flatwise tensile strength of natural sandwich panels was 14–21% higher and the specific flatwise compressive strength was 2–10% higher than the synthetic sandwich panels. The edgewise compressive strength was found to be 32–34% lower than synthetic sandwich panels. The results suggest that natural sandwich panel could be a better alternative material for building applications.

2012 ◽  
Vol 446-449 ◽  
pp. 3725-3729
Author(s):  
Wei Hua Ma ◽  
Hong Zhen Kang

Compressive tests of 30 concrete column specimens with three concrete strength grades are carried out in this paper to study ultimate compressive strength of specimens. The specimens are divided into three groups, that is, unconfined, confined by CFRP with no initial compression and confined by CFRP with various initial compressions. The different initial compressions’ influence on ultimate stresses and strains are investigated. The decrease of CFRP reinforcing effect due to pre-compression are analyzed. The research results provide experimental datum for reinforced design of existing concrete columns.


2018 ◽  
Vol 22 (5) ◽  
pp. 1426-1449
Author(s):  
SS Satheesh Kumar ◽  
M Sudhakara Rao ◽  
I Balasundar ◽  
Amit Kumar Singh ◽  
T Raghu ◽  
...  

Metallic thermal protection systems comprising of sandwich panels consisting of hexagonal honeycomb sandwich structures are envisaged to be used in advanced transportation systems like hypersonic vehicles and reusable launch vehicles. The assessment of compressive mechanical behaviour is necessary to understand the response of sandwich structures to aerothermal loads. The fabrication methodology for realizing Ni based superalloy Superni 263 hexagonal honeycomb sandwich panels is established. This work is aimed at understanding the effect of sandwich panel geometry parameters like hexagonal cell size and core thickness on the out-of-plane flatwise compressive behaviour at room temperature. The ultimate compressive strength decreases with increasing core height irrespective of the cell sizes investigated. The dependence of specific compressive strength on the cell size is established by a power law relationship. The compressed sandwich panels subjected to understand the deformation behaviour indicated the dominance of cell wall bending and occasional fracture, however in the case of sandwich panels with higher core thickness cell wall buckling coupled with shearing at the face sheet vicinity is noticed.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110094
Author(s):  
Ibrahim Elnasri ◽  
Han Zhao

In this study, we numerically investigate the impact perforation of sandwich panels made of 0.8 mm 2024-T3 aluminum alloy skin sheets and graded polymeric hollow sphere cores with four different gradient profiles. A suitable numerical model was conducted using the LS-DYNA code, calibrated with an inverse perforation test, instrumented with a Hopkinson bar, and validated using experimental data from the literature. Moreover, the effects of quasi-static loading, landing rates, and boundary conditions on the perforation resistance of the studied graded core sandwich panels were discussed. The simulation results showed that the piercing force–displacement response of the graded core sandwich panels is affected by the core density gradient profiles. Besides, the energy absorption capability can be effectively enhanced by modifying the arrangement of the core layers with unclumping boundary conditions in the graded core sandwich panel, which is rather too hard to achieve with clumping boundary conditions.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Noridah Mohamad ◽  
A. I. Khalil ◽  
A. A. Abdul Samad ◽  
W. I. Goh

This paper presents the structural behaviour of precast lightweight foam concrete sandwich panel (PFLP) under flexure, studied experimentally and theoretically. Four (4) full scale specimens with a double shear steel connector of 6 mm diameter and steel reinforcement of 9 mm diameter were cast and tested. The panel’s structural behavior was studied in the context of its ultimate flexure load, crack pattern, load-deflection profile, and efficiency of shear connectors. Results showed that the ultimate flexure load obtained from the experiment is influenced by the panel’s compressive strength and thickness. The crack pattern recorded in each panel showed the emergence of initial cracks at the midspan which later spread toward the left and right zones of the slab. The theoretical ultimate load for fully composite and noncomposite panels was obtained from the classical equations. All panel specimens were found to behave in a partially composite manner. Panels PLFP-3 and PLFP-4 with higher compressive strength and total thickness managed to obtain a higher degree of compositeness which is 30 and 32.6 percent, respectively.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3030
Author(s):  
Łukasz Smakosz ◽  
Ireneusz Kreja ◽  
Zbigniew Pozorski

Edgewise compression response of a composite structural insulated panel (CSIP) with magnesium oxide board facings was investigated. The discussed CSIP is a novel multifunctional sandwich panel introduced to the housing industry as a part of the wall, floor, and roof assemblies. The study aims to propose a computational tool for reliable prediction of failure modes of CSIPs subjected to concentric and eccentric axial loads. An advanced numerical model was proposed that includes geometrical and material nonlinearity as well as incorporates the material bimodularity effect to achieve accurate and versatile failure mode prediction capability. Laboratory tests on small-scale CSIP samples of three different slenderness ratios and full-scale panels loaded with three different eccentricity values were carried out, and the test data were compared with numerical results for validation. The finite element (FE) model successfully captured CSIP’s inelastic response in uniaxial compression and when flexural action was introduced by eccentric loads or buckling and predicted all failure modes correctly. The comprehensive validation showed that the proposed approach could be considered a robust and versatile aid in CSIP design.


2021 ◽  
pp. 1-11
Author(s):  
Thelma S. Horn

This paper is based on a Senior Scholar presentation delivered at the 2020 annual meeting of the North American Society for the Psychology of Sport and Physical Activity. The paper begins with a summary of the research work completed by the author and coinvestigators in regard to the influences that significant others (parents, peers, and coaches) exert on the psychosocial well-being of individuals in sport and physical activity. In each of these three areas, illustrative research studies are summarized in a predominantly chronological order with a commentary at the end of each section that identifies unanswered questions and suggests future research directions. In the second section, four particular lessons learned by the author over the course of a scholarly career are identified and explained.


2018 ◽  
Vol 25 (5) ◽  
pp. 927-937 ◽  
Author(s):  
Khuram Rashid ◽  
Sana Nazir

AbstractConservation of natural resources, healthy environments, and optimal utilization of waste materials are intimate needs of the present time, and this research work was carried out to fulfill these needs. In this experimental and analytical study, concrete was prepared by replacing natural fine aggregates with two types of used foundry sands by 10%, 20% and 30% (by volume). The properties of fresh and hardened concrete were investigated and compared with a replacement amount of fine aggregates from 0% to 30%. Compressive strength was evaluated after 7, 28 and 63 days of moist curing. Along with compressive strength, the modulus of elasticity was also investigated and a reduction in compressive strength and modulus of elasticity was observed with the increase in the amount of used foundry sand. A prediction formula was proposed to predict the compressive strength, and verified by current experimental observations and also with a large database that was also established in this work. The prediction formula may be considered as very helpful for predicting the potential of using used foundry sand as an aggregate in concrete.


2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zhongchang Qian ◽  
Daoqing Chang ◽  
Bilong Liu ◽  
Ke Liu

An approach on the prediction of sound transmission loss for a finite sandwich panel with honeycomb core is described in the paper. The sandwich panel is treated as orthotropic and the apparent bending stiffness in two principal directions is estimated by means of simple tests on beam elements cut from the sandwich panel. Utilizing orthotropic panel theory, together with the obtained bending stiffness in two directions, the sound transmission loss of simply-supported sandwich panel is predicted by the modal expansion method. Simulation results indicated that dimension, orthotropy, and loss factor may play important roles on sound transmission loss of sandwich panel. The predicted transmission loss is compared with measured data and the agreement is reasonable. This approach may provide an efficient tool to predict the sound transmission loss of finite sandwich panels.


2013 ◽  
Vol 420 ◽  
pp. 276-280
Author(s):  
Bashar S. Mohammed ◽  
Ean Lee Woen ◽  
M.A. Malek ◽  
Wong Leong Sing ◽  
Nor Aishah Abbas ◽  
...  

Electrical companies generate electricity mainly from two major types of plant; hydroelectric plants and thermal plants. Hydroelectric is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water through dams operation. The sedimentation of such dams over years will cause large capacity losses of the dams. Thermal plants generate electricity through coal-fired power plants which produce millions tons of fly ash yearly. This fly ash accumulates rapidly and causes enormous problems of disposal. Therefore, the research work presented in this paper is dealing with utilizing reservoir sediment and fly as to form brick under pressure. Sediment brick can be produced as a load bearing brick with compressive strength is greater than 7 N/mm2.


2014 ◽  
Vol 2 (1) ◽  
pp. 75-82
Author(s):  
Elivs M. Mbadike ◽  
N.N Osadebe

In this research work, the effect of mound soil on concrete produced with river sand was investigated. A mixed proportion of 1.1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of river sand with mound soil is 0%, 5%, 10%, 20%, 30% and 40%. Concrete cubes of 150mm x 150mm x150mm of river sand/mound soil were cast and cured at 3, 7, 28, 60 and 90 days respectively. At the end of each hydration period, the three cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength test for 5- 40% replacement of river sand with mound soil ranges from 24.00 -42.58N/mm2 a against 23.29-36.08N/mm2 for the control test (0% replacement).The workability of concrete produced with 5- 40% replacement of river sand with mound soil ranges from 47- 62mm as against 70mm for the control test.


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